With increasing demand for more information to be supplied to homes and/or businesses, many network communication providers are switching or upgrading their networks to high speed communication signaling protocol, such as Digital Signal 1 (“DS1”) or T1. High speed communication signaling protocol typically offers high speed audio, video, and data transmission to/from homes and/or businesses. For example, DS1 is capable of organizing voltage values as data signals in a serial data stream which can be transmitted over a pair of conductor wires. At the receiving end, upon recovery of clock frequencies from the data signals, a receiving circuit typically needs to identify frame and/or Extended Super Frame (“ESF”) boundaries from the data stream before the information carried by DS1 can be adequately processed.
Depending on the network environment, aligning or realigning DS1 or T1 ESF can be time consuming. Information carried by the frames or ESF can not be processed until the boundary of each ESF is identified. As such, an extended delay for realigning frames or ESF can negatively impact the overall network performance.
A conventional approach to identify a boundary of a frame or an ESF, for example, is to pick one (1) bit for every 193 bits. Upon a group of bits or picked bits are collected, the group of bits is assumed to contain information relating to frame alignment. As such, when a group of bits is collected, a frame pattern is searched within the collected bits. In one example, a frame pattern can be searched from a group of bits includes 48 bits which represent two ESFs. Two ESFs typically take 6 milliseconds (“ms”) to transmit over T1 or DS1. Upon recognizing the frame pattern, the process declares that the first frame pattern is found. Otherwise, the process selects a bit arrived later in time as a new frame bit which may contain information relating to frame alignment position, and proceeds to repeat the similar search(s) as previously described. This process continues until a frame pattern is located in the bit stream. With such conventional approach, the time required to identify a frame boundary could take as long as 1158 ms (193×6) to locate a first match of frame pattern. It should be noted that an alignment delay of 1158 ms may be too long for some applications. The alignment process could be even longer if the found alignment is a false alignment.